Snap, premiering at the SXSW Film Festival next week, is a pretty grim tale. Young stars Jake Hoffman (yes, son of Dustin) and Nikki Reed (The Twilight Saga: Breaking Dawn Part 2) have both been in their share of dark films, but their upcoming feature about a schizophrenic dubstep fan and the girl he becomes obsessed with is by far the darkest.

“This was the first time I’ve ever done a movie this creepy,” Hoffman says. “I had nightmares during the shoot.”

Check out a teaser from the film below.

Snap follows Hoffman’s character, Jim, through the world of dubstep, a music scene neither of the stars were familiar with before shooting the film, but which the directors – Youssef Delara and Victor Teran – had long been fascinated by. Their recent Sundance film, Filly Brown, also explores the world of hip hop and dubstep music.

“I know nothing about dubstep and even when we were scouting locations … I looked at the directors and I said, ‘Is this something I really need to research and thoroughly understand because this is totally foreign to me?’” Reed says. Fortunately her character Wendy is also new to the scene at the beginning of the film. “I did a little bit of research but for the most part I think Wendy is kind of removed from it. She’s not on Jim’s level with that.”

The co-stars did spend time researching mental illness, on the other hand. The two spoke with schizophrenia patients in the weeks leading up to shooting the film, and said they learned a lot by talking to people and understanding what someone with mental illness is going through. “All the people we met with, the patients, they’re sweet kids,” Hoffman says.”They were really open and brave.”

Reed adds that, “I think they were at a point in their [treatment where] they were able to break down and comprehend what this meant to them.” But she is quick to point out that while the film ties Jim’s character to violent behavior, that violence and schizophrenia “do not go hand in hand.”

Hoffman says the story is also about intimacy. “One of the things that really jumped out at me when I first read the script, that made me want to be part of it, was the concept of when couples initially come together and are attracted to each other,” he says. “It’s a thin line between being there for somebody, and at what point does it just become too heavy.”

Another surprising element to the film is that two of its stars are very familiar but for much lighter roles: Jason Priestley and Scott Bakula.

“Scott Bakula and I worked very closely with one another,” Reed says. “I just love working with people that are better than me, it can only elevate a scene and bring it to a new level.”

Snap isn’t the only thing on Reed’s agenda at the Austin festival. She’s also performing with her husband, singer and former American Idol contestant Paul MacDonald during the music portion of the festival. The two had a song on the Breaking Dawn: Part 2 soundtrack and released an album of duets earlier this year. But is she still watching Idol? “In secret, I TiVo the show and then when he’s [Paul’s] not home, I take out a tub of cookie dough and watch Nikki Minaj yell at people.”

Sounds like a good way to relax after watching the disturbing clip of Snap above.